Author

McRae, Tessa Anne

Date

1991

Advisor

Tomson, Mason B.

Degree

Master of Science

Abstract

Release of residual aviation gasoline saturation from field contaminated sandy aquifer material was investigated using six soil columns. Addition of a biodegradable non-ionic surfactant (5g/L) to the flushing solution produced an immediate increase in concentrations of methylated alkanes which declined over 20 pore volumes to below initial levels. 15g/L of surfactant produced higher effluent concentrations over 6 pore volumes. Adding 50% (v/v) 2-propanol caused a spike release of contaminants in less than 2 pore volumes.
Methanol at 50% released contaminants at fairly low concentrations over 30 pore volumes. At 20% neither alcohol produced much increase in effluent concentrations. Combination of 20% 2-propanol and 5g/L Triton X-100 did not improve the performance of surfactant alone. Soil analysis showed more than 96% of the residual saturation was removed in all six columns.
Solvophobic theory, including the effects of reduction in interfacial surface tension, predicted the relative results of both concentrations of alcohols.